Dovetailing-machine.



No. 779,183. PATENTED JAN. 3, 1905. F. J. BENZ.

DOVE'IAILING MACHINE.

APPLIGATION FILED FEB. 26, 1904.

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F. J. BENZ. DOVETAILING MACHINE.

' APPLICATION TILED FEB. 26. 1904.

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N0. mm. PATENTED JAN. 2, 1005.

F. J. BENZ.

DOVETAILING MACHINE.

APPLIGATION FILED FEB. 26. 1904.

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FRANK J. BENZ, OF ST. PAUL, MINNESOTA.

'DOVETAILING-MAQHINE.

SPECIFICATION forming part of Letters Patent No. 779,183, dated J anuary 3, 1905.

Application filed February 26, 1904. Serial No. 195.373.

To all whom, it may concern.-

Beit known that I, FRANK J. RENZ, a citi- Zen of the United States of America, residing at St. Paul, Minnesota, have invented certain new and useful Improvements in Dovetailing- Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to dovetailing-machines, and has for its object the provision of means whereby the tongue and the groove may both be accurately formed by the same machine.

In the manufacture of various articlessuch, for instance, as engravers blocks, drafting-boards, and the like-it is necessary in order to prevent warping to place in position upon the end of a board a strip in which thegrain runs in the opposite direction. Thisis done ordinarily by gluing, nailing, or dovetailing.

It has been attempted to form grooves by the use of saws inclined at an angle to each other and cutting one in advance of the other.

This arrangement and method of operation is open to many objections, such as the lateral strain tending to throw the work out of line, the extent of table-surface required in the machine, and the difficulty of gaging the out,

operate side by side and upon the same portion of the material as viewed longitudinally thereof.

In the accompanying drawings 1 have illustrated a preferred embodiment of my invention in connection with a complete machine.

In the drawings, Figure 1 represents a vertical section of the machine with the saws arranged for cutting the groove. Fig. Qis a top plan view with the cover removed and with the saws or cutters in the same position as in Fig. 1. Fig. 3 is a similar view to Fig. 1 with the cutters arranged for forming the tongue or tenon. Fig. 4 is a similar view to Fig. 2 with the cutters in the same position as in Fig. 3. Fig. '5 is a top plan view of the table with the cover in place and showing the table-slide on the line C D of Fig. 3, and Fig. 9

represents one of the saws or cutters in side and top elevation.

Referring to the drawings more in detail, (t

represents the table, in which is journaled the main driving-shaft b, carrying the pulley 0 and provided with a pair of toothed gears dd. Spiral gears a engage with the toothed gear and are mounted upon shafts ff. These shafts are inclined at an angle of preferably ten degrees to the horizontal and are journaled in boxes g g, which are slidably mounted in the brackets h it.

Upon the inner ends of the shaftsff are mounted saws or cutters z a", which are inclined at an angle of, say, ten degrees to the vertical. The several teeth of these saws or cutters are spaced apart a sufficient distance to allow the teeth of the respective cutters to intermesh when in the position shown in Figs. 1 and 2 without interfering with the operation of each other and allowing clearance for chips.

Projecting downward from the slides g g are arms j and ,7", the arm 7' being provided at its lower extremity with a threaded nut 7:: and the arm 7" provided with a bearing A spindle Z carries at one end a threaded portion m, which engages with the nut /c. A smooth portion of this spindle passes through the bearing 70 and turns loosely therein, relative longitudinal movement of the two being prevented by collars n, carried by the spindle. This shaft is operated by means of a handwheel 0. Set-screws p and p, arranged, respectively, on each side of the arms 1' and 7", impinge against these arms and serve to limit the longitudinal movement of the slides g 9 within the brackets it h.

A stationary gage q, secured to the table-top at one side of the saws, and a movable gage q upon the opposite side serve to confine the material being operated upon and hold the same in proper position for the saws, the gage q being adjustable by means of the knurled nut r. A sharp-edged wheels is mounted, by means of the pin 8, within the gage q, with its edge projecting beyond the surface of the gage in such manner as to be pressed into the surface of the material and prevent the work being raised from the table-top under the influence of the cutters. This wheel also serves a useful purpose in that it marks one side of the work for identification in assembling the parts later.

In Fig. 1, it represents a block or board in process of having a groove formed therein, while in Fig. 3 a tongue is being formed upon a board likewise identified.

As the cutters are moved to and from each other to form a tongue or groove, as the case may be, means are provided for progressively closing the top of the table and preventing the entrance of dust to the mechanism, such means consisting of plates 1; '0', having downwardly-projecting lugs to w, which engage corresponding recesses carried by the slides g 9. These plates are slidably mounted within the table-top, as shown in Fig. 8, and under the influence of the lugs w w are moved backward and forward with the slides, so that at all times the plates extend to a point close to the saws and restrict the size of the opening in the table-top.

The operation of the mechanism is as follows: If it is desired, for instance, to form in the board a a groove, the gage q is adjusted to the proper distance from the fixed gage q to receive the board. The inner one of each pair of set-screws 10 and p is so adjusted as to permit the slides g g under the influence of the hand-wheel o'and the spindle Z to be moved inward until the teeth of the cutters intermesh, as shown in Figs. 1 and 2, at a point corresponding to the position where the groove is desired to be made and to a degree corresponding to the size of the desired groove. It will be obvious that the place of making the groove may be shifted toward the fixed gage g by advancing the inner set-screw p and retracting the inner set-screw 19' upon the opposite side and that the groove may be made at a greater distance from the fixed gage by a reverse operation. This adjustment is rendered possible by the provision of the threaded nut is at the lower extremity of the arm j and the journal in upon the arm 1", as will be readily understood. As the driving-shaft b and the gears (Z and e are set in motion the cutters revolve in the direction shown by the arrow in Fig. 2, while the board 24 is fed into the machine in the same direction. The sharp edges of the intermeshing cutters act as chisels, accurately cutting the groove of the exact dimensions desired. In order to form a tongue, the hand-wheel 0 is turned to the left, and the slide is carried from a position with its cutter intermeshing with its companion cutter until the arm j instead of impinging against the inner set-screw 19, as shown in Fig. 1, abuts against the outer set-screw p, as shown in Fig. 3. Having reached this position it becomes stationary, and the slide 9 under the influence of the threaded portion of the spindle Z is moved outward until its arm instead of impinging against the inner set-screw p abuts against the outer set-screw p, the two extreme positions being likewise shown in Figs. 1 and 3. The movement of the slides g and 9 may be successive, as described, or it may be synchronous, depending upon the comparative degree of friction between the parts. By an examination of Figs. 3 and 4 it will be seen that the cutters now occupy a position for forming a tongue adapted to fit the groove, made as heretofore described. The machine is then set in operation and the material fed to the cutters, as before.

It will be seen that the same machine is adapted to form'both tongues and grooves, being arranged for either by the mere shifting of the hand-wheel 0. The set-screwsp and p having once been adjusted to a particular width of material and certain size of grooves and tongues, no further attention is required, while, as before explained, if it is desired to use wider material or to make a larger or smallertongue or groove or to form the tongue and groove at a greater or less distance from either side of the board such change is quickly and accurately made by the simple adjustment of the set-screws p and p.

The arrangement of the cutters side by side, so that they operate either at a distance apart laterally or intermeshing, as the case may be, instead of arranging them tandem, has very decided advantages, in that any tendency on the part of the work to spring away from the cutters is avoided. By this construction, moreover, the opening in the table is shortened, the table itself can be made much smaller, and any distortion of the work is avoided, as the cutters enter and leave at the same time. By this arrangement of the cutters and the adjusting and shifting mechanism also I am enabled in the same machine and by the same cutters to form both accurately-fitting tongues and also grooves. This arrangement of the cutters side by side is defined in the claims by stating that they are disposed with their axes in substantially the same plane, the word substantially excluding the requirement of mathematical accuracy, the essential feature being that the cutters are arranged with their faces in opposition to each other and operate side by side instead of one materially in advance of the other.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is

1. In a dovetailing-machine, a work-holder, and rotary cutters arranged to operate in planes converging toward the work-holder and so constructed and arranged that the cut- 3 ting-teeth of one may pass between or intermesh'with those of the other within the range of engagement with the work, the axes of the cutters lying substantially in the same plane.

2. In a dovetailing-machine, a work-holder, rotary cutters arranged to operate in planes converging toward the work-holder and so constructed and arranged that the cuttingteeth of one may pass between or intermesh with those of the other within the range of engagement with the work, the axes of the cutters lying substantially in the same plane,

and means for shifting said cutters from a po.

sition with their teeth intermeshing to a position apart from each other.

3. In a dovetailing-machine, a work-holder, rotary cutters arranged to operate in planes converging toward the work-holder and so constructed and arranged that the cuttingteeth of one may pass between or intermesh with those of the other within the range of engagement with the work, the axes of the cutters lying substantially in the same plane, and means for shifting said cutters from a position with their teeth intermeshing to a position apart from each other while maintaining the angle of inclination of the respective cutters.

4c. In a dovetailing-machine, awork-holder, rotary cutters arranged to operate in planes converging toward the work-holder and so constructed and arranged that the cuttingteeth of one may pass between or intermesh with those of the other within the range of engagement with the work, the axes of the cutters lying substantially in the same plane, and means for shifting said cutters from a position with their teeth intermeshing to a position with their teeth separated to a corresponding degree.

5; In ado'vetailingmacl1ine, a work-holder, rotary cutters arranged to operate in planes converging toward the work-holder and so constructed and arranged that the cuttingteeth of one may pass between or intermesh with those of the other within the range of engagement with the work, the axes of the cutters lying substantially in the same plane, the shaft of each cutter journaled in a box slidable upon straight ways, an arm depending from each box and a screw-spindle journaled in said arms whereby the cutters may be shifted to and from each other while maintaining the angle of inclination of the respective cutters.

6. In a dovetailing-machine, a work-holder, rotary cutters arranged to operate in planes converging toward .the work-holder and so constructed and arranged that the cuttingteeth of one may pass between or intermesh mounted loosely within the bearing and having threaded engagement with said nut and means for limiting longitudinal movement of the spindle within the journal.

7. In a dovetailing-machine, a work-holder, rotary cutters arranged to operate in planes converging toward the work-holder and so constructed and arranged that the cuttingteeth of one may pass between or intermesh with those of the other within the range of engagement with the work, the axes of the cutters lying substantially in the same plane, straight ways arranged at an angle to the axes of the shafts, boxes for said shafts slidably mounted upon said ways, arms depending from each of said boxes, a nut carried by one of the arms, a bearing. carried by the other of said arms, a spindle passing through the bearing and engaging by a threaded portion with the nut, means carried by the spindle and limiting its movement longitudinally with reference to the bearing, a hand-wheel carried by the spindle, and-set-screws so arranged as to limit the movement of the boxes to and from each other.

8. In adovetailing-machine, aWork-holder, rotary cutters arranged to operate in planes converging toward the work-holder and so constructed and arranged that the cuttingteeth of one may pass between or intermesh with those of the other within the range of engagement with the work, the axes of the cutters lying substantially in the same plane, straight ways arranged at an angle to the axes of the shafts, boxes slidably mounted upon the ways and serving as bearings for said shafts, arms depending from each of said boxes, a nut carried by one of said arms, a bearing carried by the other of said arms, a spindle passing through the bearing and engaging with a threaded portion the nut, means for limiting the movement of the spindle longitudinally of the bearing, a hand-wheel carried by the spindle, and set-screws arranged on each side of and adapted to impinge on each of said arms.

In testimony whereof I affix my signature to this specification in the presence of two witnesses.

FRANK J. REN Z. 

